1. Field of the Invention
The present invention relates to a head-protecting airbag device whose airbag is mountable on an upper periphery of a window of a vehicle at an inboard side of the vehicle in a folded-up configuration with an upper edge thereof secured to a vehicle body structure and is deployable downward over the window when fed with an inflation gas.
2. Description of Related Art
In an known head-protecting airbag device as disclosed in JP2008-6895A (Literature 1), JP2010-202187A (Literature 2), JP2013-52748A (Literature 3), JP2014-162313A (Literature 4) and JP2012-20719A (Literature 5), an airbag includes an airbag body for covering an inboard side of a window of a vehicle, a terminal inflatable portion which is disposed at the front end region of the airbag body as deployed in such a manner as to be partitioned from a remaining general inflatable portion of the airbag body, and a connecting member which connect the front end region of the airbag body to the vehicle body structure. The connecting member is arranged over the outboard side of the terminal inflatable portion. A first end (or root end) of the connecting member is jointed to a terminal partitioning portion which partitions the terminal inflatable portion from the general inflatable portion while a second end (or leading end) of the connecting member is adapted to be fixed to the vehicle body structure at a periphery of the window. At airbag deployment, a tension force occurs in the connecting member generally along a front and rear direction of the airbag and the connecting member supports the outboard side of the terminal inflatable portion such that the terminal inflatable portion protects an occupant's head in the event of an oblique collision.
While the connecting member of the head-protecting airbag device disclosed in the Literature 5 is formed into a band, each of the connecting members in the Literatures 1 to 4 has such a sheet shape as to cover a considerable area in an up and down direction of the outboard side of the terminal inflatable portion. However, in the head-protecting airbag devices disclosed in the Literatures 1 to 4, a straight joint extending generally along an up and down direction joints the connecting member to the airbag body. With this configuration, although the joint joints the connecting member to the airbag body over an extended area in an up and down direction, the tension force exerted in the connecting member occurs only on a line connecting the leading end (second end) of the connecting member to be fixed to the vehicle body structure and a point on the joint which makes the shortest distance to the leading end in direct distance. Accordingly, an improvement is desired in order to exert a tension force in a wider area in an up and down direction in the connecting member in a steady fashion.